Collagen gel and process of producing the same

Abstract

The present invention relates to a process of producing a collagen gel comprising collagen fibers cross-linked with each other by a cross-linking agent on the way of fibrosis of collagen, and a collagen gel comprising the cross-linked collagen fibers obtained by the process. The collagen gel comprising cross-linked collagen fibers of the present invention has high strength and thermal stability and can be widely used as cell carriers and medical materials.

1. A process of producing a collagen gel comprising cross-linked collagen fibrils, said process comprising:
 (a) cross-linking collagen fibrils with each other during fibril formation by mixing (i) a collagen solution, 
 (ii) a cross-linking agent, wherein the collagen does not form fibrils with the cross-linking agent, and 
 (iii) an aqueous solution of a phosphate, the aqueous solution having a buffering ability, and serving as a solvent, thereby inducing fibril formation and cross-linking occur simultaneously, and 
 (b) recovering a collagen gel comprising cross-linked collagen fibrils. 
 
     
     
       2. The process of producing a collagen gel according to  claim 1 , wherein collagen obtained from fish is used. 
     
     
       3. The process of producing a collagen gel according to  claim 1 , wherein the cross-linking agent is in the form of a solution prepared by dissolving a water-soluble carbodiimide in the aqueous solution of a phosphate. 
     
     
       4. The process of producing a collagen gel according to  claim 1 , wherein the collagen solution has a collagen concentration of 0.01 to 3.0 (w/v) %. 
     
     
       5. The process of producing a collagen gel according to  claim 1 , wherein the cross-linking agent used is in the range of 15 to 80 mM as a final concentration of the cross-linking agent in the collagen gel. 
     
     
       6. The process of producing a collagen gel according to  claim 1 , wherein mixing the collagen solution with the phosphate solution and with the cross-linking agent is carried out at a temperature lower than the denaturation temperature of the collagen. 
     
     
       7. The process of producing a collagen gel according to  claim 6 , wherein, after mixing of the collagen solution, the phosphate solution and the cross-linking agent, the resulting mixture is incubated for at least one hour at a temperature lower than the denaturation temperature of the collagen. 
     
     
       8. The process of producing a collagen gel according to  claim 1 , wherein the cross-linking agent is selected from the group consisting of at least one of the following:
 a carbodiimide-based cross-linking agent, an epoxide-based cross-linking agent, an aldehyde-based cross-linking agent and an imidazole-based cross-linking agent. 
 
     
     
       9. The process of producing a collagen gel according to  claim 1 , wherein the cross-linking agent is in the form of a water-soluble carbodiimide. 
     
     
       10. The process of producing a collagen gel according to  claim 1 , consisting of the steps of cross-linking and recovering. 
     
     
       11. A process of producing a collagen gel comprising cross-linked collagen fibrils, said process comprising:
 (a) cross-linking collagen fibrils with each other during fibril formation by mixing 
 (i) a collagen solution, and 
 (ii) a solution of a cross-linking agent, wherein the collagen does not form fibrils with the cross-linking agent, and, then mixing with the mixture of (i) and (ii) 
 (iii) an aqueous solution of a phosphate, the aqueous solution having a buffering ability, and serving as a solvent, thereby inducing fibril formation and cross-linking simultaneously, and, 
 (b) recovering a collagen gel comprising cross-linked collagen fibrils.